Unstable frame kinoton fp30

[Javier de Blas]

Before you panic too much and start pulling things apart, I had a stability problem with
a polyester print a few months ago, and it turned out to be a problem with the print, and
not with the projector. We have a 2-proj change-over system, and although the problem
showed up on both projectors, it was a little worse on one than on the other. Setting the
gate tension on the Century JJ's to maximum fixed it on the right-side projector, although
I still had some jitter on my left side machine.

BUT THIS FIXED IT!
JitterStopper.jpg

I've run more than a dozen different 35mm features since then, (without the
rubber band) and haven't had problems. It was just that one stupid polyester print.
I was actually surprised the rubber band didn't melt, since the gate & trap, even though
water cooled, still gets pretty hot with our 4.5k Xenons, but it survived all week OK.

I hope it's something like that. Because it's true that some prints jitter more than others. For example, my copy of marie antoinette jitters like crazy no matter what I do. But on the other hand some other prints like shrek 2 only jitter a little tiny bit that seems like I'm the only one who notice and others like premonition don't jitter at all.

[Javier de Blas]

It’s possible the omega spring, which applies gate tension, is wearing out and needs to be replaced. Ideally gate tension would be at no more than 2/3 for polyester films.

I found out later that giving more tension doesn't really fix the problem, actually I get almost the same result with a third of the tension (that point were the copy stops been loud) than going like crazy.

[Javier de Blas]

To check if it is a bad/shaky printing, remove the aperture plate and pan to where the sprockets are visible on screen, if they are stable but image is not definitely the print. Hard to do during a show of course!

I'll try that. Thank god this is my home set up. Not the DP70 of the cinema where I work. So that's no problem at all.

[Brad Miller]

Before you panic too much and start pulling things apart, I had a stability problem with
a polyester print a few months ago, and it turned out to be a problem with the print, and
not with the projector.

What was the print title? Kodak started making the base thinner some time ago which is why prints have been more easily scratched and slight blemishes now project. More recently they switched to some other company making their film base (I think I heard Germany, but don't quote me) and it's even thinner now...AND it's inconsistent. For theaters with shallow depth of focus, that can be a real problem on base-side-registered gate/traps. For all systems though, this new stock almost scratches itself if you give it a dirty look. (Kodak is going to end up killing film itself with this nonsense.)

On your JJ, you might want to have the spring in the trap closing knob checked. It doesn't sound like it's quite strong enough (or the mechanism is a bit gunked up) such that it's not 100% closing without a little extra pressure (from your rubber band).

[Brad Miller]

I found out later that giving more tension doesn't really fix the problem, actually I get almost the same result with a third of the tension (that point were the copy stops been loud) than going like crazy.

That's just printed-in bouncing from printing at too high of speed and worn-out printer sprockets. Deluxe was NOTORIOUS for this, especially at their Canada lab using the B&H Model K printers. This was never an issue with a print from a Technicolor lab, even their high speed prints were impressively steady.

A quick check on your FP30 is to just put your finger on the skate just below the image opening and give a little extra pressure. If it doesn't stabilize, it's printed in. Also beware when adjusting skate alignment not to set the skate too high. Leave enough clearance room at the 6:00 position of the intermittent sprocket so thick splices can pass through without tugging on the skate...otherwise you will wear out the splices and cause them to break as well as slowly wear out the bottom curvature of the skate such that it ends in a point instead of a gentle curve. A safe rule of thumb is to leave a DVD's thickness of space between the 6:00 position of the intermittent and the skate.

[Jim Cassedy]

What was the print title?

I'm going to have to go back through my notes (which I don't have handy at
the moment) to find it. But if my memory is correct, it was a recent title, and
not one of the rep films we play here. Give me a day or so to check. - JC-